Feedback and servo control for electric power steering systems
US6370459B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 18, 2001 |
| Grant date | Apr 9, 2002 |
| Priority date | — |
| Expiry date | Jan 18, 2021 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB62D6/008
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
Vehicle power steering systems (710, 760, 810 and 910) achieve substantially linear control relationships between and applied steering torque input Ts and a resulting steering force output, that is, a powered assist to vehicle steering. Impedance matching means utilized for coupling an electric motor (26) to the steering load respectively include speed reduction means (712), torque summing means (812) and force generating means (912) in the systems (710, 760, 810 and 910). The speed reduction means (712) comprises gear reduction means (722) and a supplemental pinion. The torque summing means (812) comprises steering column (814) coupled gear reduction means (822), and, the force generating means (912) comprises hydraulic transmission means including a power cylinder (18). The systems (710, 760, 810 and 910) are preferably regenerative. The systems (710, 716, 810 and 910) each utilize internal closed-loop servo control of the electric motor (26) to substantially eliminate stability control problems including, for example, a low frequency stability control problem which has typically not been overcome in prior EPS systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.